Change TARGET_RECOVERY_UI_LIB to use fully qualified names in zuma

Since the TARGET_RECOVERY_UI_LIB for each device is not exactly the
same, and most of the modules in it contain `soong_namespace{}` to
avoid conflicts between different devices, after converting
`librecovery_ui_ext` from Android.mk to Android.bp, it needs to be
changed to a `fully qualified name` in order to correctly use the
corresponding module.

Flag: EXEMPT refactor

Bug: 339143524
Test: m -j librecovery_ui_ext
Change-Id: I2912cbc905ff0ee716c293021c29061e3b6d3dca